1. Field of the Invention
The present invention relates to smoking articles, for example and particularly, but not exclusively cigarettes.
2. Brief Description of the Prior Art
The ratio of the weight of carbon monoxide to the weight of tar delivered in the mainstream smoke of cigarettes is usually unity or more, although in some cases the ratio is as low as 0.9. By "tar" is meant particulate material measured on a water and nicotine-free basis. It has now been discovered that, if a novel configuration of cigarette-design features is observed, it is possible to obtain significantly lowered CO:tar delivery ratios. Moreover by use of the invention, low CO:tar ratios may be realised without incurring expense and manufacturing problems associated with the use of materials which have been proposed for removing carbon monoxide from cigarette smoke by chemical means.